The following correction was printed in the Observer's For the record column, Sunday January 20 2008

In the article below we described those who salvaged cargo from the grounded MSC Napoli as 'wreckers'. Wreckers lured vessels ashore before murdering their crews and plundering the cargo; clearly not the case here.

Somewhere in the south-west, unridden and hidden from public view, are the most infamous motorbikes in Britain. When the decision was taken to ground the cargo ship MSC Napoli off the coast of Devon a year ago because of rough weather, 103 of the containers she was carrying fell into the sea. Most came ashore at Branscombe, sparking one of the biggest wrecking incidents in recent years.

The most valuable items were the 17 new BMW bikes found in one container. Two vanished, two were seized by the police, and the remaining 13 are still with the people who found them, concealed, until legal ownership is finally resolved.

Jack Pyne, 23, whose father, Colin, runs the Bedford Hotel in Sidmouth, just a few miles down the coast from Branscombe, has one of the bikes. He went over to the beach with a couple of friends late on a Sunday night after seeing the local TV news. 'It was all pitch black, but you saw containers just up the beach. We'd heard about the bikes,' he said.

'I asked who was in charge. They were like, "It's just a queuing system - if you help other people, they help you." So, one after another, we helped. We were looking at people, checking how many bikes were left and then it came to us. We didn't know what was in it, what colour, what model, we just went, "That one." So we pulled it down. It wasn't wet, it wasn't damaged, it wasn't dented. It was absolutely spotless - no water damage, like BMW claim.'

There were keys in the ignition, a little petrol in the tank, and somehow the three of them rolled and rode the bike away. The following day, they filled in the necessary forms and sent them off to the receiver of wreck.

A year later Pyne brings the bike out of its hiding place for a photograph. It's the first time that the bike has moved since they found it.

Concerned about its reputation, BMW still says it wants the bikes back. It has offered £260 for each one, claiming that they are damaged by salt water and the fall from the ship. The 'keepers' all believe the bikes are worth far more than that, so BMW's offer was universally rejected.

The receiver of wreck, acting as broker between the two sides, is still trying to reach a solution. If that isn't possible, then the matter would have to be settled in court. Apart from the bikes and the barrels, the Napoli also contained BMW spare parts, cat food, tractor components, carpets, several copies of the Bible in Xhosa, women's make-up and anti-wrinkle cream ('I tried some,' says Colin Pyne, Jack's father. 'It didn't work').

Opinion on the wreckers is still divided - some call them 'despicable', while the beachcombers themselves consider it 'the best thing that ever happened to Devon'. What does Jack Pyne feel about the suggestion he was a wrecker? 'It's not every day a container ship gets beached outside your back garden. For local people it's all right, but I wouldn't go down to Cornwall to get pickings from a ship beached down there. I wouldn't bother - it's of no interest.'

Unlike Jack Pyne, Julian Temperley knew exactly what to do with the oak barrels he got hold of. He runs a cider distillery in Somerset, and bought or traded as many barrels as he could find.

'We've actually put them to the use for which they were intended. If the general public had got hold of them, they would either have set them on fire to keep themselves warm or they would have taken them back to their houses and cut them up for flowerpots. It would be criminal if we'd just ignored them,' Temperley said. 'There's always been a fascination in wrecks - if wrecks didn't happen, Cornwall wouldn't have a tourist industry.' And if someone called him 'despicable'? 'I feel absolutely no guilt whatsoever, no moral quandary at all. I think it was a thoroughly fun event. There were absolutely no victims. The ship had crashed all by itself. I think we should actually feel proud of taking the initiative to use the damn things - I only wish I'd been a bit less dopey and gone down on the Sunday.'

Others were not so cheerful. Peter Pritchard, sector manager of the Lyme Regis Coastguard, feels that not everyone benefited from the Napoli. 'You say nobody got hurt - nobody got seriously injured, but the impact on the community and the distress, the emotional distress, was enormous. There was violence on the beach, physical intimidation - it was absolutely mad.'

He felt the incident was badly handled by the police. 'We didn't expect it to all kick off. But then on the Monday, of course, it did. The police allowed these people on the beach and to start ransacking the cargo. The hordes of locusts descended.'

For as long as there have been ships, there have been wrecks, and for as long as there have been wrecks there have been wreckers. The story of the Napoli wasn't new, nor was the behaviour of the people who took her cargo.

Though there has never been a single line in all of English or Scottish law to suggest that finders should be keepers, the sense persists in people's minds that things claimed from the sea are somehow different to those claimed on land.

The authorities say that lessons have been learnt. The next time a general cargo wreck occurs, they will use the Theft Act or use health and safety legislation instead of trying to apply obscure salvage law.

But 2,000 years of maritime history suggests that it takes considerably more than the law to keep a good wrecker down.

· Bella Bathurst is the author of The Wreckers - A Story of Killing Seas, False Lights and Plundered Ships, published by HarperCollins